Railway switch control apparatus



May 17, 1%38. s R. PFLASTERER RAILWAY SWITCH CONTROL APPARATUS Filed April 8, 1957 W m; Q V m HIS ATTOR N EY Patented May 17, 1938 UNITED STATES PATENT A OFFICE RAILWAY swrron CONTROL APPARATUS Application April 8, 1937, Serial No. 135,678

12 Claims.

My invention relates to railway switch control apparatus.

I shall describe one form of railway switch con trol apparatus embodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form of railway switch control apparatus embodying my invention.

Referring to the drawing, the reference character M designates a motor operatively connected, by suitable means not shown in the drawing, with a railway track switch W. As here shown, the motor M is of the well-known electro- 15, pneumatic type controlled by a lock magnet L, a

normal magnet N, and a reverse magnet R.

When the normal magnet N is energized, the

motor M will becaused to drive the switch W to its normal position, as shown in the drawing, provided lock magnet L is also energized, and when the reverse magnet R is energized, the motor M will be caused to drive switchW to its reverse position provided lock magnet L is also energized. The switch W controls a pair of pole changing contacts 2 and 3 and also a contact 4 by suitable and well-known means in accordance with the switch position. That is, when switch W is in its normal position, contacts 2, 3, and 4 are in engagement with contacts 5, 6, and 7, respectively, and when switch W is in its reverse position, contacts 2, 3, and 4 are in engagement with contacts 8, 5, and 9, respectively.

The reference character WR designates a polarized switch control relay which is reversibly governed by a lever A. The reference character KR designates a polarized switch indication relay which is controlled by switch pole changing contacts 2 and 3 and by switch control relay W'R. The reference character FR designates a timing device here shown as a relay having a slow pick-up characteristic. The reference character RR designates another timing device here shown as a relay having a slow pick-up slow release characteristic. The pick-up time of timing relay FR and the pickup and release times of timing relay RR are of substantially equal lengths and, as will be explained more in detail hereinafter, the operating times of these relays are of such values that the switch W will have ample time to move from one extreme position to the other before the timing relays complete their operation.

, With all apparatus in its normal condition, as shown in the drawing, polarized switch control relay WR is energized in the normal direction by a circuit which passes over a path from terminal B of any suitable source of energy through contact l0ll of lever A, relay WR, and contact l2l 3 of lever A to terminal C of the same source of energy. Normal magnet N is energized by a circuit which passes from terminal B through normal polar contact |4-|5 of relay WR, back point of contact [6 of timing relay FR, and normal magnet N to terminal 0. Polarized switch indication relay KR is energized in the normal direction by a circuit which passes over a path from terminal B through switch contact 2--5, relay KR, normal polar contact I7-l8 of switch control relay WR, and switch contact 3-6 to terminal C.

I shall now assume that the operator desires to cause switch W to move from its normal position to its reverse position. He may do this by reversing lever A which will establish a circuit to energize switch control relay WR in the reverse direction. This circuit may be traced from terminal B through contact [9-42 of lever 'A, relay WR, and contact II20 of lever A to terminal 0. As a result, polar contacts l4 and H of switch control relay WR will move to the right to energize reverse magnet R and to deenergize switch indication relay KR. The circuit for reverse magnet R may be traced from terminal B through reverse polar contact I l-4| of relay WR, back point of contact 22 of timing relay FR, and reverse magnet R to terminal C. The releasing of switch indication relay KR closes its back neutral contact 23 to energize lock magnet L. When lock magnet L and reverse magnet R are energized, motor M will be caused to move switch W to its reverse position. The closing of back neutral contact 23 of switch indication relay KR also energizes timing relay FR over an easily traced circuit which includes front neutral contact 24 of switch control relay WR. If switch W is not obstructed so that its movement to the reverse posi tion is completed in the usual operating time of the switch, indication relay KR will become energized to disconnect energy from timing relay FR before relay FR becomes picked up. The circuit for energizing relay KR when switch W is in its reverse position and switch control relay WR is energized in the reverse direction may be traced over a path which passes from terminal B through switch contact 2,-8, reverse polar contact ll25 of switch control relay WR, relay KR, and switch contact 3-5 to terminal C.

If, however, the switch W becomes obstructed by, for example, a piece of coal or ice so that it fails-to attain its reverse position before timing relay FR becomes picked up, then motor M will be removed from control by switch control relay WR and placed under control by auxiliary timing relay RR. The opening of back point of contact 22 of timing relay FR will deenergize reverse magnet R and the closing of front point of contact l6 of relay FR will energize normal magnet N so that switch W will be restored to its normal position. The circuit for energizing normal magnet N may be. traced from terminal B through reverse polar contact I l-2| of switch control relay WR, back point of contact 26 of timing relay RR, front point of contact I 6 of timing relay FR, and normal magnet N to terminal C. When switch W is restored to its normal position, a circuit will be established for energizing auxiliary timing relay RR. This circuit may be traced over a path from terminal B through switch contact 4-1, front point of contact 2T of timing relay FR, and relay RR to terminal C. When, timing relay RR attains its picked up condition, a circuit will be established to energize reverse magnet R to cause motor M to drive switch W towardsits reverse position. This circuit may be traced from terminal B through reverse polar contact l4 2l of switch control relay WR,front point of contact 26 of relay RR, front point of contact 22- of relay FR, and reverse magnet R to terminal C.

When the contact 26 of relay RR is picked up, the circuit through its back point of contact to the normal magnet N is interrupted so that the motor M is free to move the switch W to its reverse position.

When the relay RR picks up and establishes the circuit to the reverse magnet R, the motor M drives the switch W away from the normal position towards the reverse position.

As soon as the switch W is moved away from the normal position the contact 4- is moved. out of engagement with the contact 1, thereby interrupting the circuit to the winding of the reverse relay RR. However, because of the slow release characteristic of the relay RR, it will not release instantaneously when the circuit to its winding is interrupted, but will maintain the circuit to the reverse magnet R for a time interval long enough to complete movement ofthe switch to the reverse position if the switch is functioning properly. If. the object which is obstructing the. switch. becomes crushed so that the switch W completes its movement to the reverse position, switch indication relay KR will. become energized over its previously traced reverse control circuit so that timing relay FR will become deenergized to restore the control of motor M to switch. control relay WR. If, on the other hand, the switch W fails to attain its reverse position on this movement, timing relay RR will become released since it isdeenergized because switch contact 4 will be in engagement with neither contact 1 nor contact 9. When timing relay RR attains its release condition, normal magnet N will again become energized over its p'reviously traced circuit including back point of contact 26 of timing relay RR and front point of contact 16 of timing relay FR so. that. motor M will be caused to, restore switch W to its normal position. When switch W attains its normal position, timing relay RR will again become energized over its pre- I vi'ously traced circuit to go throughanother cycle of operation as just described. In other words, as long as switch W fails to attain its reverse position, the auxiliary timing relay RR will become alternately picked up and released to drive the switch back and. forth between its normal position and an intermediate position at which it became obstructed until such time as the object which is obstructing the switch points is crushed to permit the switch W to attain its reverse position.

It will be noted that the control circuit for the timing relay FR includes front neutral contact 24 of switch control relay WR. If lever L is restored. to its normal position while timing relay FR is in its picked up condition to place the motor M under control by auxiliary timing relay RR, it will be apparent that the opening of front contact 24 due to the reversal of current in switch control relay WR will release timing relay FR to place motor M again under control by switch control. relay WR.

While I have described the operation of the apparatus embodying my invention during a movement of the switch W from its normal position to its reverse position, it will be readily apparent that the apparatus wi-lloperate-in a similar manner if the switch becomes obstructed while moving from its reverse position to its normal position.

Oneadvantage of apparatus embodying my invention is that due to repeated and automaticback and forth movement of the-switch, when the switch is prevented from reaching one extreme position or the other by some obstruction, the obstruction may bebroken downafter a few operations of theswitch so that the switch can complete its movement to-the desired position.

If desired, a suitable signal may be provided toindicate when theswitch has failed to complete its movement. For example, a light or a bell, or both, may be controlled by relay FR in 1. In combination, a railway track switch capable of assuming a first or a second position, a motor for operating said switch, manually controlled means for causing said motor to drive said switch from said. first position to said second position, and meansfor causing said motor to restore said switch to said first position. if theswitch fails to attain its. second position within a, predetermined time interval.

2. In combination, a railway track switch capable of assuming a. first or a second position, a motor for operating. said switch, manually controlled means for causing said motor to drive said switch from said first positionto said second position, timing means responsive to. the length of time required by said switch to attain its second position, and means controlled by said timing means for at times causing. said motor to. restore said switch to said first position.

3; Incombination, a railway'track switch capable of assuming a first or a second position, a motor for operating said switch, manually controlled means for causing said motor to drive said switch from said first position to said secondposition, timing means which becomes operated if said switch fails to attain its second position TLUF within a predetermined time interval, and means for causing said motor to restore said switch to said first position when said timing means is operated.

4. In combination, a railway track switch capable of assuming a first or a second position, a motor for operating said switch, manually controlled means for causing said motor to drive said switch from said first position to said secend position, means for causing said motor to restore said switch to its first position if the switch fails to attain its second position within a predetermined time interval, and means effective thereafter to cause said motor to repeatedly drive said switch to an intermediate position and then back to said first position until the switch does move from said first position to said second position within said given time interval.

5. In combination, a railway track switch capable of assuming a first or a second position, a motor for operating said switch, manually controlled means operable between a first position and a second position to cause said motor to drive said switch to its first and second positions respectively, means effective when said manually controlled means and said switch are out of correspondence for a predetermined length of time to cause said motor to alternately drive said switch towards its two positions until such time as said switch and said manually controlled means do occupy corresponding positions.

6. In combination, a railway track switch capable of assuming a first or a second position, a motor for operating said switch,.manually controlled means operable between a first position and a second position to cause said motor to drive said switch to its first and second positions respectively, an indication relay which becomes deenergized only if said manually controlled means and said switch are out of correspondence, and means effective when said indicationv relay remains deenergized in excess of a predetermined time interval to cause said motor to alternately drive said switch towards its first and second positions until such time as said indication relay again becomes energized.

'7. In combination, a railway track switch having a normal position and a reverse position, a motor operatively connected to said switch, manually controlled means for causing said motor to drive said switch from said normal position to said reverse position, a slow pick-up relay, means for energizing said relay while said switch is moving from said normal position to said reverse position, and means effective if said relay does become picked up to cause said motor to restore said switch to said normal position.

8. In combination, a railway track switch having a normal position and a reverse position, a motor operatively connected to said switch, manually controlled means for causing said motor to drive said switch from said normal position to said reverse position, an indication relay which becomes released while said switch is moving from said normal position to said reverse position, a slow pick-up relay, a circuit for said slow pickup relay including a back contact of said indication relay, and means effective to cause said motor to restore said switch to said normal position if said slow pick-up relay does become picked up.

9. In combination, a railway track switch having a normal position and a reverse position, a motor operatively connected to said switch, a switch control relay, means for energizing said switch control relay to cause said motor to drive said switch from said normal to said reverse position, a slow pick-up relay, means including a front contact of said control relay for energizing said slow pick-up relay while said switch is moving from said normal position to said reverse position, and means effective if said slow pick-up relay does become picked up to remove said motor from control by said control relay and to cause said motor to restore said switch to said normal position.

10 In combination, a railway track switchcapable of assuming a first position or a second position, a motor for operating said switch, manually controlled means for causing said motor to drive said switch between said two positions, a timing relay which becomes picked up if said switch fails to move from one position to the other within a predetermined time interval, an auxiliary slow pick-up slow release relay, a contact which is closed only when said switch is either in its first position or second position, a circuit for said auxiliary relay including said contact and a front contact of said timing relay, and means eifective when said timing relay is picked up to cause said motor to drive said switch from one position to the other according as said auxiliary relay is picked up or released.

11. In combination, a railway track switch capable of assuming a first position or a second position, a motor for operating said switch, a first magnet efiective when energized to cause said motor to drive said switch to said one position, a second magnet effective when energized to cause said motor to drive said switch to said second position, a timing relay which becomes picked up if said switch fails to move from one position to the other within a predetermined time interval, a contact which is closed only if said switch occupies its first or second position, an auxiliary relay having a slow pick-up slow release characteristic, means including said contact and a front contact of said timing relay for governing said auxiliary relay, a first circuit for said first magnet including a back contact of said timing relay, a first circuit for said second magnet including a back contact of said timing relay, a second circuit for said first magnet including a front contact of said timing relay and a back contact of said auxiliary relay, a second circuit for, said second magnet including a front contact of said timing relay and a back contact of said auxiliary relay, a third circuit for said first magnet including a front contact of said timing relay and a front contact of said auxiliary relay, and a third circuit for said second magnet including a front contact of said timing relay and a front contact of said auxiliary relay.

12. In combination, a railway track switch having two positions, means for moving said switch from either position to the other position, time controlled means which becomes energized upon the initiation of such a movement, and means governed by said time controlled means for indicating when the switch fails to complete its movement within a predetermined time interval.

GEORGE R. PFLASTERER. 

